The subject matter disclosed herein relates to heating systems. More specifically, the subject disclosure relates to burners for residential and commercial heating systems.
Heating systems, in particular furnaces, include one or more burners for combusting a fuel such as natural gas. Hot flue gas from the combustion of the fuel proceeds from the burner and through a heat exchanger. The hot flue gas transfers thermal energy to the heat exchanger, from which the thermal energy is then dissipated by a flow of air driven across the heat exchanger by, for example, a blower.
A typical prior art construction is shown in FIG. 1. A burner 100 is located external to a heat exchanger 102. The burner 100, often referred to as an inshot burner 100, receives a flow of fuel from a fuel source 104. An ignition source 106 combusts the flow of fuel to create a combustion flame 110.
Another type of burner is a premix burner in which fuel and air are mixed in a burner inlet tube prior to injection into a combustion zone 112 where the ignition source 106 ignites the mixture. Premix burners, compared to inshot burners, typically emit much lower levels of nitrogen oxide (NOx), the emissions of which are tightly regulated and restricted by many jurisdictions. Because of this advantage of premix burners, it may be desirable to utilize premix burners in furnaces.
In multi-burner applications such as furnaces, each heat exchanger is typically supplied with hot combustion products by individual burners. Typically, each burner is mounted to a partition plate of the burner assembly with a metallic flange to direct the flow of hot combustion products towards the heat exchanger. As the flame exits each burner, the flame flows across each burner flange causing the flange to become hot. Due to the highly conductive nature of the flange, the heat of the flame is transferred to the partition plate via the flanges, resulting in damage and/or deformation of the partition plate.